The present invention relates to a device for manufacturing wrapping sheets provided with related handles.
In particular, the present invention relates to a device for manufacturing wrapping sheets for packaging paper rolls taken individually or in groups constituted by a plurality of paper rolls, positioned adjacent to each other and aligned, whereto the present description shall explicitly refer without thereby losing its general nature.
According to the prior art in the paper roll industry, the paper rolls are packaged within related wrapping sheets, each of which is obtained from a first strip of heat-sealable material, is wrapped around one or more paper rolls to form a paper roll package, and is associated to a handle able to allow the consumer conveniently to grip the package itself.
Generally, the handles are obtained from a second strip of heat-sealable material, whose width is smaller than the width of the first strip, is superposed to the first strip, and is joined to the first strip by means of a coupling device that is normally able to seal or glue the two strips.
Once the two strips are joined and a third strip of heat-sealable material is obtained, the wrapping sheets and the related handles are obtained in succession by cutting the third ribbon transversely to a direction of advance thereof.
The known devices described above have some drawbacks, mainly deriving from the tact that the solutions adopted by said devices for joining the aforesaid first and second strip are relatively complex and entail in one case heat-shrinking phenomena, which occur at the end of the sealing operation, are located solely in the area of superposition of the two ribbons, and can, therefore, cause said superposition area to be shortened and narrowed relative to the remaining part of the wrapping sheet, compromising the correct formation of the roll package, and in the other case the known problems connected with the use of glue.